The location path language XPath is of particular importance for XML applications since it is a core component of many XML processing standards such as XSLT or XQuery. In this paper, based on axis symmetry of XPath, equivalences of XPath 1.0 location paths involving reverse axes, such as ancestor and preceding, are established. These equivalences are used as rewriting rules in an algorithm for transforming location paths with reverse axes into equivalent reverse-axis-free ones. Location paths without reverse axes, as generated by the presented rewriting algorithm, enable ecient SAX-like streamed data processing of XPath.

XML specifications often consist of a type definition (typically, a DTD) and a set of integrity constraints. It has been shown previously that such specifications can be inconsistent, and thus it is often desirable to check consistency at compile-time. It is known that for general keys and foreign keys, and DTDs, the consistency problem is undecidable; however, it becomes NP-complete when all keys are one-attribute (unary), and tractable, if no foreign keys are used.

Abstract. XQuery is widely used for querying XML documents. Within this paper, we examine optimization rules for XQuery queries that exploit type information of the input XML document given in XML Schema. These optimization rules are applicable for all XQuery expressions and are very useful e.g. in the scenario of XQuery queries on XQuery views. The basic idea is to transform the XML Schema definition into a graph, which is extended to a graph representing the XQuery expression. The latter graph is used to delete subexpressions of the XQuery expression that are not used to retrieve the final result of the given XQuery expression. We further include experimental results that demonstrate the improvement of our optimization. 1

Abstract. XML-based network management has been proposed as an alternative or to complement SNMP-based network management. But the XML-based network management does not yet provide a method to manage networks equipped with legacy SNMP agents in the integrated management system. This integrated management system must include an XML/SNMP gateway, which translates and relays messages between the XML-based manager and the SNMP agent. In this paper, we propose three methods for interaction translation in the gateway. First, we propose a DOM-based translation, which provides a method for XML-based manager to directly access management information through the standard DOM interfaces. Second, we propose an HTTP-based translation using URI extenstion with XPath and XQuery. Finally, we apply SOAP, which is accepted as a standard protocol for XML, and propose a translation method for the gateway to advertise the translation services to the manager using SOAP RPC. We also compare the advantages and disadvantages of the proposed translation methods. 1

The usage of computer applications in the construction industry has steadily increased over the years, as has the complexity of many software applications. It is difficult for project personnel to become familiar with these ever-increasingly complex tools. Furthermore, the causes of many practical problems, such as project delays or escalating costs, are often not obvious from the outputs of these tools. A question answering system can potentially provide a means to directly extracting answers from these computer outputs. This paper examines various issues involved in building such a question answering system. In particular, emerging industry standards, such as ifcXML, are adopted as the knowledge representation format, and thus alleviate the manual effort to build a knowledge base. We explore the mechanisms of utilizing information in the knowledge base for question understanding. A prototype question answering system has been built and tested to illustrate the potential usefulness of such a system for project management applications.

XML speci cations often consist of a type de nition (typically, a DTD) and a set of integrity constraints. It has been shown previously that such speci cations can be inconsistent, and thus it is often desirable to check consistency at compile-time. It is known that for general keys and foreign keys, and DTDs, the consistency problem is undecidable; however, it becomes NP-complete when all keys are one-attribute (unary), and tractable, if no foreign keys are used.

Abstract XPath is a language for addressing fragments of XML documents, used in query and transformation languages such as XQuery and XSLT. For many applications it is desirable to process XPath on the fly and progressively against data streams. This diploma thesis is devoted to streamed and progressive evaluation of XPath.

There is an increasing interest within the reverse engineering community in using the XML language and its related technologies as a way to foster the development, reuse and interoperability of code analysis tools. However, most of the work done in this direction has thus far concentrated on the interoperability issue, mainly with the proposal of new XML-based source code representations, and the development of new facilities for extracting those representations from source code. This paper attempts to fill this gap by showing how XML-based source code representations and query technologies can be used to facilitate the development and reuse of code analysis tools. 1.

Abstract. This paper combines data grid and web services techniques with information mediation and online mapping approaches to outline a scalable infrastructure for ubiquitous mapping where heterogeneous spatial data can be discovered, accessed, queried, integrated and visualized as maps on both desktop and mobile devices. The grid services infrastructure elements we describe, are being developed within GEON (the Geosciences Network) project. The focus of the paper is services that support ubiquitous mapping: from federating multiple spatial data sources to assembling composite maps from heterogeneous map fragments on user queries, and to delivering vector map content to various devices. We present system-independent abstractions of integrated views used by GEON mediation services for generating composite maps, tracing them from XQuery specification to implementation using grid services.

The usage of computer applications in the construction industry has steadily increased over the years, as has the complexity of many applications. However, project managers, who are usually responsible for making decisions, are not necessarily familiar with these ever-increasingly complex applications. As a result, a question answering system is needed for efficiently managing construction projects. In this paper, we examine the various aspects involved in building a question answering system. In particular, we use ifcXML files as the knowledge representation system, which require no manual efforts to build the knowledge base. Moreover, we explore the mechanism to utilize information in the knowledge base for question understanding. A prototype question answering system, based on various technologies, has been built and successfully tested on several construction projects.